Method of assembling a wheel assembly for a ground-driven work machine

ABSTRACT

A wheel assembly for a work machine, such as a mining dump truck, comprises a rotatable wheel having inboard and outboard rims mounted thereto. The outboard rim is mounted to a segmented rim-mounting flange which is secured to the inboard side of a flange projecting from the wheel. A final drive adapter is secured to the outboard end of the wheel opposite the segmented rim mounted flange. The segmented mounting flange permits the use of a larger final drive ring gear than in known wheel assemblies. Moreover, because the mounting flange is segmented, it can be fastened to the wheel inboard of the gear reduction housing, which permits the final drive assembly to be serviced without removal of the outboard rim from the wheel. Related methods are also disclosed.

This is a divisional application of application Ser. No. 09/070,412,filed Apr. 30, 1998 now U.S. Pat. No. 6,148,941.

TECHNICAL FIELD

This invention relates to a wheel assembly for a ground-driven workmachine, such as a dump truck or the like, and a method for assemblingsuch a wheel assembly.

BACKGROUND ART

Large earth working machines, such as mining dump trucks for example,typically have at least a pair of driven wheels which are rotatablymounted upon corresponding axle housings or spindles. Each wheel isdriven through a final drive reduction gear train, which is typically adouble-reduction planetary arrangement, drivingly connected with acylindrical final drive adapter that partially surround the final drivering gear. The final drive adapter connects planetary arrangement withthe wheel and may be either a separate component fastened between theplanet carrier of the planetary arrangement and the wheel or may be anintegral portion of the planet carrier itself. The adapter is secured tothe outboard end of the wheel, and a drive axle extending through theaxle housing drives the final drive adapter, and thereby the wheel, viathe final drive reduction gear train. Power to drive such earth workingmachines is typically provided by an internal combustion engine whichdrives the aforementioned drive axles either through a mechanicaltransmission and differential arrangement or through generation ofelectrical power to operate electric motors coupled with the driveaxles.

It is common for each wheel to carry two rims with ground-engaging tiresmounted thereto, namely an inboard rim and an outboard rim. Prior knownconfigurations are typically assembled by sliding the inboard rim overthe final drive adapter and along the wheel to a rim-mounting flangeprojecting radially from the wheel to which the inboard wheel isfastened. An outboard rim adapter, which comprises a one-piece ring, isthen slid over the final drive adapter from the outboard end thereof andfastened thereto to provide a radially-projecting outboard rim-mountingflange. The outboard rim is then slid over the final drive adapter andfastened to the outboard rim-mounting flange. Alternatively, the adapterring may be first fastened to the outboard rim, and the rim/adapter ringcombination can then be slid over the final drive adapter and fastenedthereto.

Wheel and rim configurations as described above are found, for example,on Model 793C mining trucks sold by Caterpillar Inc., Peoria, Ill., andon GDY85C AC motorized wheels manufactured by GE Transportation Systems,such wheels being found on Model 930E mining trucks sold by KomatsuHaulpak, Peoria, Ill.

Although the known wheel arrangement described above is satisfactory forcurrent machine configurations, larger machines with larger payloads areconsidered desirable to achieve better hauling efficiency. As machinesincrease in size to accommodate larger payloads, the need for morerobust drive train components is paramount, which typically means theuse of larger components. For example, it is desirable in trucks whichuse a planetary final drive to utilize as large a ring gear asreasonably possible to reduce stress on the drive train and increasecomponent life. However, prior art constructions limit the size of thefinal drive ring gear because the final drive housing must be smallenough for the inboard rim to slide over the final drive adapter, whichpartially surround the final drive ring gear and for a one-piece rimadapter ring to be fitted around the final drive adapter from theoutboard end thereof as described above.

In addition, because the outboard rim in known constructions is fastenedto an adapter ring mounted to the outboard end of the final driveadapter, such known constructions require removal of the outboard rimprior to removal of the final drive ring gear for repair or replacement.As a result, it is necessary to raise the outboard tire from the groundand support the machine with jacks or the like in order to remove theoutboard rim and service the final drive.

The present invention is directed to overcoming one or more of theproblems described above.

DISCLOSURE OF THE INVENTION

In one aspect of this invention, a wheel assembly for a work machinecomprises a rotatable wheel having at least one radially-outwardlyprojecting flange. A first rim is mounted to the wheel for rotationtherewith at a location spaced from the at least one flange. Pluralflange segments are fastened to the at least one wheel flange to form asegmented radially-outwardly projecting rim-mounting flange. A secondrim is mounted to the wheel for rotation therewith, the second rimhaving a radially-inwardly projecting flange fastened to the segmentedrim-mounting flange.

In another aspect of this invention, a wheel drive assembly for use in aground-driven work machine comprises a rotatably-fixed axle housing anda rotatable drive axle extending through the axle housing. A wheelassembly as described above is mounted for rotation about the axlehousing and drivingly connected with the drive axle.

In still another aspect of this invention, a work machine adapted to bepropelled across ground comprises a frame, a drive power supply mountedto the frame, and at least one wheel drive assembly as described abovemounted to the frame. The drive axle of the at least one wheel driveassembly is rotatably driven by the drive power system.

In another aspect of this invention, a wheel and reduction gear assemblyfor use in a ground-driven work machine comprises a rotatable wheelhaving inboard and outboard ends, a reduction gear assembly, and agenerally cylindrical reduction gear adapter drivingly connected betweenthe reduction gear assembly and the outboard end of the wheel forrotation therewith. Inboard and outboard rims are mounted to the wheelfor rotation therewith. Each of the rims has a radially-inwardlyprojecting mounting flange fastened to the wheel, each of the mountingflanges having an inside diameter. The outside diameter of the reductiongear adapter is substantially equal to the inside diameter of themounting flange of the inboard rim.

In a further aspect, a wheel and reduction gear assembly for use in aground-driven work machine comprises a rotatable wheel having inboardand outboard ends, a reduction gear assembly, and a generallycylindrical reduction gear adapter drivingly connected between thereduction gear assembly and the outboard end of the wheel for rotationtherewith. An inboard rim is mounted to the wheel for rotationtherewith, and a rim mounting ring is fastened to the wheel for rotationtherewith at a location spaced from the inboard rim. An outboard rim ismounted to the rim mounting ring. The rim mounting ring is fastened tothe wheel at a location inboard of the reduction gear adapter such thatthe reduction gear assembly is removable from the wheel without removalof the rim mounting ring or the outboard rim from the wheel.

In yet another aspect of this invention, a method for assembling a wheeldrive assembly for a ground-driven work machine is provided. A wheelhaving at least one radially-outwardly projecting flange is mounted onthe axle housing for rotation about the housing. A first rim is mountedto the wheel for rotation therewith. Plural flange segments are securedto the at least one wheel flange to form a segmented rim-mounting flangeon the wheel. A second rim is mounted to the wheel for rotationtherewith, the second wheel being fastened to the segmented rim-mountingflange.

Other features and advantages will be apparent from the followingdescription and the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a side elevational view of a mining dump truck with which thisinvention may be used.

FIG. 2 is a cross-sectional view showing a fully assembled wheel driveassembly in accordance with this invention.

FIG. 3 is a perspective view of a partially-assembled wheel driveassembly in accordance with this invention.

FIG. 4 is perspective view similar to FIG. 3 but showing a later stagein the process of assembling the wheel drive assembly.

FIG. 5 is a perspective view similar to FIGS. 3 and 4 but showing stilla later stage in the assembly process.

FIG. 6 is a fragmentary, enlarged perspective view of a portion of thewheel drive assembly illustrated in FIG. 5.

FIG. 7 is a diagrammatic representation of a mechanical-drive powertrain utilizing wheel drive assemblies in accordance with thisinvention.

FIG. 8 is a diagrammatic representation of a portion of an electricdrive power train utilizing wheel drive assemblies in accordance withthis invention.

BEST MODE FOR CARRYING OUT THE INVENTION

FIG. 1 illustrates an off-highway or mining truck, generally designated10, with which this invention may be used. Although the truck 10 may beof any suitable construction, the illustrated truck 10 is a two-axletruck comprising a frame 12, a material-carrying dump body 14 pivotallymounted on the frame 12, and an operator cab 16 mounted atop an engineenclosure 18. The truck 10 is supported on the ground by front tires 20(only one of which is shown) and rear tires 22 (only one of which isshown). As well known, one or more engines (not shown in FIG. 1) aretypically mounted to the frame 12 and housed within the engine enclosure18.

Referring also to FIG. 2, the rear tires 22 on each side of the truck 10are mounted on a wheel drive assembly, generally designated 24, whichincludes a wheel assembly 26, a spindle or axle housing 28, a finaldrive assembly, shown diagrammatically at 30, and a drive axle 32. Asconventional, the wheel assembly 26 is mounted for rotation about theaxle housing 28 using suitable roller bearing or the like. Although notimportant to this invention, a conventional oil-cooled disc brakemechanism, illustrated diagrammatically at 33, is typically provided toslow or stop rotation of the wheel assembly 26 relative to the axlehousing 28. The final drive assembly 30 may be a conventionaldouble-reduction planetary final drive which is well known in the artand is, therefore, not described in significant detail herein.Generally, however, the final drive assembly 30 preferably comprisesfirst (inboard) and second (outboard) ring gears 34, 36, severalcorresponding planet and sun gears (not shown), and an outer planetcarrier 37. A cylindrical final drive adapter, generally designated 38,is bolted or otherwise connected between the outboard end of the wheelassembly 26 and the planet carrier 37, and is rotatably driven by thefinal drive assembly 30. Alternatively, the final drive adapter 38 maybe defined by an integral portion of the planet carrier 37 that surroundthe ring gear 26, rather than a separate component between the planetcarrier 37 and the wheel assembly 26. Such integral planet carrier/finaldrive adapter arrangements are known in the art and are not discussed infurther detail herein. As apparent, rotation of the drive axle 32 istransmitted through the final drive assembly 30 to the final driveadapter 38 and thus to the wheel assembly 26 to cause rotation of thewheel assembly 26 relative to the axle housing 28.

With continued reference to FIG. 2, the wheel assembly 26 comprises awheel 44, an inboard rim 46, a rim adapter ring 48, and an outboard rim50. The wheel 44 has a radially-outwardly projecting annular flange 52formed thereon at its inboard end which is used to mount the inboard rim46 to the wheel 44. Referring also to FIG. 3, the flange 52 has pluralstuds 54 projecting therefrom toward the outboard end of the wheel 44.Each of the studs 54 has an enlarged head at one end and a shaft whichextends through an aperture in the flange 52. The portion of the studshaft which is received with the flange 52 is splined to retain the studtherein, and the projecting portion of the shaft is threaded.

The inboard rim 46 has a radially-inwardly-projecting annular mountingflange 56 which has apertures therein that align with and receive thestuds 54. The inboard rim 46 is slid concentrically over the final driveadapter 38 and the wheel 44 from the outboard end thereof until thestuds 54 are received within the apertures in the inboard rim flange 56.Thereafter, nuts 58 are threaded onto the studs 54 to secure the inboardrim 46 to the wheel 44, as shown in FIGS. 2 and 4. For reasons whichwill be discussed below and as apparent from FIG. 2, the inside diameterof the inboard rim mounting flange 56 is substantially equal to theoutside diameter of the cylindrical final drive adapter 38.

Referring now to FIGS. 2 and 5, the adapter ring 48 comprises pluralarcuate segments 48A and 48B which are fastened to an annular flange 60projecting radially-outwardly at the outboard end of the wheel 44. Thering segments 48A, 48B together provide an annular outboard rim mountingflange 62 that is larger in outside diameter than the wheel 44 and thefinal drive adapter 38. As shown in FIG. 6, the outboard rim 50 ismounted to the wheel 44 by sliding the rim 50 concentrically over thefinal drive adapter 38 and fastening the rim 50 to the mounting flange62, as will be discussed in greater detail below.

The illustrated adapter ring 48 comprises only two arcuate segment 48A,48B which extend in substantially uninterrupted fashion substantially360 degrees around the wheel 44. However, it will be understood thatmore than two ring segments may be used, and the particulars ofembodiments utilizing more than two ring segments will be apparent fromthe following description. In addition, one skilled in the art will alsorecognize that adapter ring 48 need not extend around the wheel withoutsubstantial interruption.

With reference to FIGS. 2, 5 and 6, each adapter ring segment 48A, 48Bis provided with mounting studs 64 which may be similar to the studs 54described above with regard to mounting of the inboard rim 46. Forreason which will be described, however, the studs 64 at confrontingends of the ring segments 48A, 48B preferably have a tab-like head 66having an aperture 68 extending therethrough. The studs 66 arepreferably installed on the ring segments 48A, 48B prior to assembly ofthe ring segments 48A, 48B onto the wheel 44. As apparent, the studs 66are received within aligned apertures in a radially-inwardly projectingmounting flange 70 of the outboard rim 50, and nuts 72 are threaded ontothe studs 66 to fasten the rim 50 to the adapter ring 48 and thereby thewheel 44.

The adapter ring segments 48A, 48B are assembled onto the wheel 44 byfirst aligning the segments 48A, 48B axially with the flange 62 as shownin FIG. 5. As shown particularly in FIG. 6, the ring segments 48A, 48Bare then piloted onto the flange 62 by extending a bolt 74 throughaligned apertures 68 in the studs 66 at each end of the segments 48A,48B. A nut 76 is then threaded onto the bolt 74 and tightened to drawthe ring segments 48A, 48B against the radially-outwardly-facing surfaceof the flange 62. Here, it will be noted that slight gap preferablyremains between confronting ends of the ring segments 48A, 48B. Once thering segments 48A, 48B are so piloted onto the flange 62, the segments48A, 48B are then fastened to the flange 62 by bolts 78 (only one ofwhich is shown in FIG. 5). The bolts 78 extend through the flange 62 andinto the final drive adapter 38 to thereby fasten both the ring segments48A, 48B and the final drive adapter 38 to the wheel 44. In thisrespect, it will be noted that the bolts 78 are preferably not threadedinto the wheel flange 62, but instead simply pass through the flange 62.

Referring again to FIG. 2, the bolted joint between the bolted jointbetween the wheel 44, the adapter ring segments 48, and the final driveadapter 38 is located radially inwardly of the radial outer wall of thefinal drive adapter 38, and the outboard end of the wheel 44 is radiallysmaller than the final drive adapter 38 as well as the outboard ringgear 30. This configuration permits the bolted joint between the wheel44, the adapter ring segments 48, and the final drive adapter 38 tooccupy the radial space surrounding the inboard ring gear 34.

FIGS. 7 and 8 diagrammatically illustrate portions of power trainarrangements which utilize wheel drive assemblies 24 as described above.FIG. 7 illustrates a so-called mechanical drive power train, whichincludes at least one internal combustion engine 80, a multi-gearmechanical transmission 82, a differential 84, and a pair of wheel driveassemblies 24 in accordance with this invention. The engine 80,transmission 82, and differential 84 may be of any suitableconstruction, may be conventional, and are, therefore, not describedfurther herein. As well known, an output shaft (not shown) of the engine80 is coupled with the transmission 82, and the output of thetransmission 82 is coupled with the differential 84 to drive the axleshaft of each wheel drive assembly 24.

FIG. 8 illustrates a portion of a so-called electric drive power train.The axle shaft 32 of each wheel drive assembly 24 is driven by asuitable electric motor 86, and the electric motors 86 are operated by asuitable controller 88. Electric power for the motors 86 is typicallyprovided by a generator (not shown) powered by one or more internalcombustion engines (not shown) mounted to the frame 12 of the truck 10.Electric drive power trains as illustrated in FIG. 8, except forparticular wheel drive assembly described herein, are well known in theart and the details thereof are not important to an understanding of thepresent invention. Therefore, the electric motors 86 and controller 88are not described in further detail herein.

INDUSTRIAL APPLICABILITY

The construction described above provides several advantages over thewheel and rim constructions previously known in the art. Moreparticularly, because the adapter ring 48 is segmented and fastened tothe wheel 44 instead of the final drive adapter 38, the final driveadapter 38 may be substantially the same diameters as the insidediameter of the inboard rim 46. Thus, outboard ring gear 36 of the finaldrive assembly 30 may be as large as possible for a particular rim size,thereby minimizing stress on the drive train and extending the life ofthe final drive assembly 30 and other power train components. Theconfiguration of the outboard end of the wheel and the bolted jointbetween the wheel 44, the adapter ring segments 48, and the final driveadapter 38 also contribute to the ability to use a large outboard ringgear 30.

In addition, the final drive adapter 38, except when integral with theplanet carrier 37, need not be removed from the wheel 44 in order forthe final drive assembly 30 (and particularly the ring gear 36) to beserviced or replaced. Therefore, the final drive assembly 30 (andparticularly the ring gear 36) may be serviced or removed with the truck10 supported on its own tires. The truck 10 need not be jacked up orotherwise supported above the ground in order to fully service the finaldrive assembly 30 or even remove it from the wheel assembly 24 in itsentirety.

Although the presently preferred embodiments of this invention have beendescribed, it will be understood that within the purview of theinvention various changes may be made within the scope of the followingclaims.

What is claimed is:
 1. A method for assembling a wheel drive assemblyfor a ground-driven work machine, said wheel drive assembly comprisingan axle housing, said method comprising the steps of: mounting a wheelon said axle housing for rotation about said housing, said wheel havingat least one radially-outwardly projecting flange; mounting a first rimto said wheel for rotation therewith; securing plural flange segments tosaid at least one wheel flange to form a segmented rim-mounting flangeon said wheel; and mounting a second rim to said wheel for rotationtherewith, said second rim being fastened to said segmented rim-mountingflange.
 2. The method of claim 1 wherein said first rim has aradially-inwardly projecting mounting flange, and wherein said first rimmounting step comprises sliding said first rim along said wheel suchthat said mounting flange of said first rim passes over said at leastone flange projecting radially from said wheel.
 3. The method of claim 2wherein said first rim comprises an inboard rim and said second rimcomprises an outboard rim.
 4. The method of claim 1 wherein said wheelhas inboard and outboard ends, wherein said at least one wheel flangehas inboard and outboard sides, and wherein said plural flange segmentsare secured to the inboard side of said wheel flange.